diff --git a/src/_zkapauthorizer/_plugin.py b/src/_zkapauthorizer/_plugin.py
index 6d7a705ded6cc369809c28dc2dcf4e8f079c6f37..0d38e95133d11d13ed913275d66aa7d61ba5da30 100644
--- a/src/_zkapauthorizer/_plugin.py
+++ b/src/_zkapauthorizer/_plugin.py
@@ -22,6 +22,11 @@ from datetime import datetime
 from functools import partial
 from weakref import WeakValueDictionary
 
+try:
+    from typing import Callable
+except ImportError:
+    pass
+
 import attr
 from allmydata.client import _Client
 from allmydata.interfaces import IAnnounceableStorageServer, IFoolscapStoragePlugin